A plastic release button on millions of Japanese-made seat belts is being investigated by federal automotive safety regulators because of a surge in seat belt failures. The belt supplier, Takata Corp. of Tokyo, has furnished belts for most Japanese cars sold in the United States, except Toyotas.
About 6 million to 10 million vehicles may be involved in the investigation.
``We don't know what is happening. We still haven't found the root cause. That's part of the analysis,'' said Reid Rundell, president of Takata Inc. in Auburn Hills, Mich., a 6-year-old subsidiary of Takata Corp.
``These are buckles that were made in Japan. The button ma-terial at the time was ABS and the leading edge of the button under certain conditions would have little pieces chipped out,'' Rundell said.
``It's an end-release buckle and because the pieces would fall into the mechanism in some cases you couldn't latch the belt,'' he said.
Rundell said similar situations arise when other things such as coins and hair pins fall into the latching mechanisms.
Japanese Synthetic Rubber Co. Ltd. of Tokyo made the resin for the buttons in question, Rundell said.
Part of the analysis being done by the National Highway Traffic Safety Administration is determining how many vehicles are involved, he said.
``Each of the manufacturers, who have the warranty and claim data, are working with NHTSA to determine the root cause and whether it is indeed a problem and how serious it is,'' Rundell said.